I would get this checked out by a doctor. Considering that you were sick it could be a post-viral syndrome.
This type of onset is almost exactly what I had when my CFS hit. The only thing that doesn't match is the groin pain. As soldy mentioned, this is most likely due to an unrelated testicular (vaginal?) cysts, but could be several other things as well, so get that checked out by a doctor.
The best thing I found for the weak feelings is to exercise very lightly, but regularly. DO NOT PUSH YOURSELF. Always stay well below what you think you can do. If you're saying "I think I can do another set", stop now. Unlike regular people, people with CFS or FMS who push themselves will become increasingly exhausted, deteriorating over time. If you constantly stay under what you can do, though, you'll find your overall stamina will begin to build. If it is indeed CFS, expect that this will take months or years to achieve anything significant, though.
Having said all that, there are a number of other conditions that can cause similar symptoms ranging from B12 deficiency all the way up to Lupus. So here again, get a doctor to check things out. If they're puzzled and can't find anything, it's probably CFS or FMS.
If you are arm curling 100 lbs. 50 times i'd say that's pretty great. Sometimes, when we have a serious infection it takes time to return to good health because of the toll it takes on the body.
You really should get back with your physician about the residual symptoms, in order to find out what is going on. Could it be FMS or CFS...it could be, but I don't think anyone with these conditions can do anywhere near what you have described in relations to exercise. I pray you have neither of these.
Take care of yourself.
Hi,
Can you locate on your body cysts painful to touch